Flask



FIG. 1 is front elevational view of a flask embodying my new design, the rear elevational view being a mirror image;

FIG. 2 is right side elevational view thereof, the left side elevational view being a mirror image;

FIG. 3 is a front perspective view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a front elevational view thereof, shown with the cap removed; and,

FIG. 6 is a rear elevational view of FIG. 5.

The parallel lines in the figures are shading lines indicating surface contours. 

I claim the ornamental design for a flask, as shown and described. 